1. Field
The present invention relates to a drying apparatus, one example of which is used in a coater drier which dries the material coated by a thin film, etc. with a coating machine, etc.
2. Description of the Related Art
Patent document 1 Japanese Patent Laid-Open Publication 2012-172960
Patent document 2 Japanese Patent Laid-Open Publication 2012-139657
Patent document 3 Japanese Patent Laid-Open Publication 2004-230265
The technology disclosed in patent document 1 is to spray hot gases at about Centigrade 50-300° C. (let all temperature be “Centigrade” henceforth) on a substrate surface processed by painting. In this case, it is necessary to install the hot gas generating furnace provided with a heater etc., and an energy expenditure at the time of operation of the furnace becomes large.
The technology disclosed in patent document 2 is to carrying out by a cooling coil concentration recovery of exhaust air from a drier, which contains a high-concentration N-Methyl-2-pyrrolidone (NMP) solvent, to return the high-concentration system exhaust air from the drier to an inlet side of the drier and to carry out condensation recovery of a part of gas by passing the part of the gas through an adsorption rotor. A part of air which passed through a treatment area of the adsorption rotor is returned to an outlet side of the drier as low-concentration system drier exhaust air.
However, the technology disclosed in patent document 2 has a problem that, since the exhaust air including a high-concentrated NMP is returned to the inlet side where the NMP generating concentration is comparatively high, the dry efficiency of NMP falls. Also, since a part or the whole quantity of gas which comes out of the treatment area of the adsorption rotor is exhausted to outdoors, an energy loss is generated.
The technology disclosed in patent document 3 is that the humidity of purification gas is very high since water is used for processing of exhaust gas. An installation of a dehumidifier etc., is needed to reduce humidity in order to reuse the gas as air for dryness. Accordingly, the disclosed technology requires an initial cost and a high running cost. Also, as to the technology, a lot of water is needed and a rate of solvent recovery becomes comparatively low with about 80%. Further, it is necessary to process the water containing solvent, and sanitation facilities for water are needed.